Yes. definitely. Different concentration of solvents yield different composition of secondary metabolites. As Intan safinar Ismail said, methanol is the best suited solvent for plant extraction in which we get from the range of non polar to polar compounds. But extremely non polar is extracted with petroleum ether and extremely polar is extracted with water. Thus water extracts yield mostly sugars and glycosides. methanol with different concentration of water yields different compounds.

Thanks for the answers. By the way, can we state that 80% of methanol extracted more chemical compounds compare to 40% methanol?

One of the major advantages of methanol is that it causes cell lysis - sometimes releasing Non polar compounds.  So it is sometimes helpful to  do a "total" methanol or methanol water extraction, evaporate and then back extract with less polar solvents such as hexane

its depend on te chemical constituent that you want extract.

Hi Hazwani,

I guess everything is clarified regarding the influence of solvente concentration and polarity. You should always pay attention to the solvente to solid ratio, which can affect greatly the extraction yield. Furthermore, you should consider the aimed application; I certainly would not choose methanol to obtain extracts to include in food applications...

All answers are very well. No more in addition.

your best solvent to extract most active phytochemicals is 70 % ethanol 

for terpens you can try hexane 

Yes, almost all answers are very well, one thing is clear that different solvents and their concentration has an important role in extraction of herbs, the chemical profile in quantity and quality differs.

Plants contain structurally diverse different types of chemical constituents having affinity/solubility with solvents of varying polarity. Various solvent or solvents mixture in different ratio result in extraction of different compounds as well as varying quantity of total extract.  Methanol is regarded as the most appropriate organic solvent to extract most of the polar compounds. However, adding water to methanol in the ratio of M:W- 80:20 or 70:30  further increase the polarity of the solvent mixture which is suitable for recovery of highly polar compounds from a polar-non polar mixture.

Methanol is known toxic, chances of residual traces are there; instead of methanol ethyl alcohol and water in 50:50 or 80:20 may be better.

I fully agree with previous researcher that it differs with different concentrations of solvent mixtures. Only I would like to add here that you should mention % of alcohol with which solvent. Let it is understood that it will be water only. But one should always mention concentration of one solvent with another solvent. In your question it is not clear, but it is fact that the concentration and content will always different with different concentrations. 

You may try solvent-less methods like supercritical extraction using carbon dioxide which can evaporate at normal temperatures making the work-up easy. It will also achieve comprehensive extraction

I agree with Dr. Rathod you should mention % alcohol  with which solvent, but anyway, the extraction of the  compounds depend on its polarity. You can find many examples in the scientific journals as Phytochemistry or  J of Natural Products.

 I think that if we want to extract all compounds with different polarities we need to use mixtures of methanol / water with different ratios to get most polar and non-polar compounds. Many examples ,you can find in scientific journals.

Methanol/Water will not extract non-polar compounds. You have to use solvents or solvent mixture of varying polarity to extract all compounds (non or less-polar, medium polar and highly polar). Based on the polarity of the compounds, different solvents ratio in mixture will give you different extraction of compounds. 

Yes, Because of the difference in solvent polarity

What is purpose of using different concentrations of solvent to extraction of the plant . Because to get concentrated liquid you are evaporating the solvent then cinematographic separation is done. It is easy to remove volatile solvent than non-volatile.Instead of methanol you can use ethanol for polar compds. which is cheaper but do not use water for extraction.

Effect of solvent polarity on extraction yield and antioxidant properties of phytochemicals from bean (Phaseolus vulgaris) seeds.

https://www.scielo.br/scielo.php?pid=S1984-82502020000100501&script=sci_arttext

We used different concentrations of solvent to extract the plant .Higher conc. & more polar solvents yields are higher.

I think combination of methanol-water will be good for most of the compounds from polar-non polar.

You should be find a good Reference to compare the defferences.

Also, the time and method of extraction are the most important in obtaining the largest amount of extract